ActiveProject(2013-2014)
Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProjectCenterInnovationFund:JSCCIF(AlsoIncludesJSCIRAD)ProgramSpaceTechnologyMissionDirectorate(STMD)
AtStart:2 Current:2 AtEnd:4
1 2 3 4 5 6 7 8 9
AppliedResearch Development Demo&Test
NASA/JSCPropulsionandPowerDivision
ProjectTechnologyMaturity
ABSTRACT
Thermionic(TI)powerconversionisapromisingtechnologyfirstinvestigatedfor
powerconversioninthe1960’s,andofrenewedinterestduetomodernadvances
innanotechnology,MEMS,materialsandmanufacturing.Benefitsincludehigh
conversionefficiency(20%),staticoperationwithnomovingpartsandpotential
forhighreliability,greatlyreducedplantcomplexity,andthepotentialforreduced
developmentcosts.Thermionicemission,creditedtoEdisonin1880,formsthe
basisofvacuumtubesandmuchof20thcenturyelectronics.Heatcanbe
convertedintoelectricitywhenelectronsemittedfromahotsurfacearecollected
acrossasmallgap....Readmoreonthelastpage.
TechnologyArea: SpacePower&EnergyStorageTA03(Primary)In-SpacePropulsionTechnologiesTA02(Secondary)
ANTICIPATEDBENEFITS
ToNASAunfunded&plannedmissions:Thisprojecttargetsonethemostcriticalbarrierstohumandeepspaceexploration–the
meanstoefficientlypowerandrapidlypropelhumanmissionstoMarsandbeyond.The
projectwillexploretheimplementationofahighefficiency“Solid-State”Thermionic-based
nuclearfissionpowersystemstoserveElectricPropulsionsystemssuchasQ-thrusters,
VASIMR,Hall,orotherapproaches.ASolid-Stateapproachcenteredaroundadvanced
Thermionicpowerconverterswouldcombinethehighefficiencyoftraditionaldynamic
powerconversion(Rankine,Brayton,Stirling)withthesimplicityofastaticconverterwith
nomovingparts.Theresultingsystem...
Readmoreonthelastpage.
Printed4/4/2014 1
https://ntrs.nasa.gov/search.jsp?R=20140004416 2018-05-19T07:55:55+00:00Z
DETAILEDDESCRIPTION
Thermionic(TI)powerconversionisapromisingtechnologyfirstinvestigatedforpowerconversion
inthe1960’s,andofrenewedinterestduetomodernadvancesinnanotechnology,MEMS,
materialsandmanufacturing.Benefitsincludehighconversionefficiency(20%),staticoperation
withnomovingpartsandpotentialforhighreliability,greatlyreducedplantcomplexity,andthe
potentialforlowDesign,Development.TestandEvaluation(DDT&E)costs.Thermionicemission,
creditedtoEdisonin1880,formsthebasisofvacuumtubesandmuchof20thcenturyelectronics.
Heatcanbeconvertedintoelectricitywhenelectronsemittedfromahotsurfacearecollected
acrossasmallgap.Forexample,two“small”(6kWe)ThermionicSpaceReactorswereflownby
theUSSRin1987-88foroceanradarreconnaissance.HigherpoweredNuclear-Thermionic
powersystemsdrivingElectricPropulsion(Q-thruster,VASIMR,etc.)mayofferthebreakthrough
necessaryforhumanMarsmissionsof<1yrroundtrip.
...
Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
MANAGEMENT
ProgramExecutive:JohnFalker
ProgramManager:RonaldGClaytonProjectManager:JeffreyGeorge
Printed4/4/2014 2
U.S.stateswithwork
Leadcenter:JohnsonSpaceCenter
Supportingcenters:GlennResearchCenter,MarshallSpaceFlightCenter,NASAHeadquarters
Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
DETAILEDDESCRIPTION(CONT'D)
Thisprojecttargetsonethemostcriticalbarrierstohumandeepspaceexploration–themeanstoefficientlypower
andrapidlypropelhumanmissionstoMarsandbeyond.Theprojectwillexploretheimplementationofahigh
efficiency“Solid-State”Thermionic-basednuclearfissionpowersystemstoserveElectricPropulsionsystemssuch
asQ-thrusters,VASIMR,Hall,orotherapproaches.ASolid-StateapproachcenteredaroundadvancedThermionic
powerconverterswouldcombinethehighefficiencyoftraditionaldynamicpowerconversion(Rankine,Brayton,
Stirling)withthesimplicityofastaticconverterwithnomovingparts.TheresultingsystemcouldenableHuman
Marsmissionsof<1yearroundtripbyaffordingasystemofmegawattpower,lowspecificmass(<10kg/kWe),
greatlyreducedplantcomplexity,andassociatedsavingsindevelopmentcost.
Thisprojectprovidestheinitialfoundationandconfidenceforhighefficiencysolid-statepowerconverters,andearly
definitionofenabledhumanexplorationsystemsandmissions(ex.MegawattElectricPropulsion,Moon/Mars
SurfacePower).Subsequentconverterdevelopmentwillimprovereadinessandlifetime,leadingto“flightready”
articles.AnintermediateNASAinfusionstepwoulddemonstratekilowatt-classnuclearpowersystemsapplicableto
MoonorMarssurface.HumanvehiclesystemdevelopmentwouldthenintegratetheseconverterswithDOE
nuclearreactortechnology,NASAbalanceofplant(ex.radiators,PMAD),andelectricpropulsion(ex.Q-thrusters,
VASIMR,Hallthrusters)todevelopan“ultimate”NASAapplicationofaHumanMarsMegawatt-classNuclear
ElectricPropulsionvehicleandmission.Terrestrialapplicationswouldbeinformed/infusedresultinginhigh
efficiencypowersystemswithgreatlyreducedcomplexityandcost.
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Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
TECHNOLOGYDETAILS
AtStart:2 Current:2 AtEnd:4
1 2 3 4 5 6 7 8 9
AppliedResearch
Development Demo&Test
Solid-StateThermionic
NuclearPowerfor
MegawattPropulsion,
PlanetarySurfaceand
CommercialPower
TechnologyMaturity
ProjectDevelopmentPhases(3Years)
YearOne:Concepts,Missions,NanomaterialsEmission,LabConverterDemo.
Multi-MegawattNEPsystem&Marsmissionconcepts,modelsandanalysis.
Research&designofpracticalThermionicConverters.
Fabricatenanostructuredthermionicemittersofvarioussurfacesize&features.
Test&characterizethermionicemissionforvariousnanomaterials.
Examples:Tungsten,BaOcoated,alignedcarbonnanotubes,
nanocrystallinediamond
Demonstratethermionicpowerconversioninalaboratoryconfiguration.
Assess“modern”potentialtoincreaseefficiency,reduceoperationalemission
temperature,increasepowerdensity.
ExploreapplicabilitytosmallerpowersystemsfordeepspaceorMoon/Mars
surface,aswellaspotentialforsimpler,morecosteffectiveterrestrialnuclear
powerplants.
YearTwo:BreadboardConverterDDT&E.
YearThree:BrassboardConverterDDT&E
Thistechnologyiscategorizedasahardwaresystemformannedspaceflight
TechnologyArea
TA03SpacePower&Energy...
PerformanceMetrics
Metric Unit Quantity
PowerConversionEfficiency(atMaturity) % 20
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Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
TECHNOLOGYDETAILS
TECHNOLOGYDESCRIPTION(CONT'D)Storage(Primary)
TA02In-SpacePropulsionTechnologies(Secondary)
CAPABILITIESPROVIDEDThermionicconvertershaveaveryhighpotentialforDualUse.Commercialpowerplants,nuclearorotherwise,
wouldbenefitfromhighefficiencypowerconversionwithreducedplantcomplexity,maintenanceandcapitalcosts.
AnuclearplantbaseduponThermionicconversionmaybewellsuitedtomeetingDepartmentofEnergy(DOE)
goalsforitsnext-generationSmallModularReactorprogram.Atsmallerscales,successfulloweringoftheelectron
emissionthresholdwouldalsoallowThermionicconverterstoperformpowerscavengingorbottomingfrom
otherwise“wasteheat”.ThermionicswoulddoubletheefficiencyandrecoveryofThermoelectric“tailpipe”
convertersbeingdevelopedtoharnessautomotiveexhaustenergy,replacingelectricalalternatorsandeliminating
theirparasiticdragontheengine.
POTENTIALAPPLICATIONS1.SpaceNuclearPowerSystems
2.SpaceSolarPowerSystems
3.TerrestrialCommercialNuclearPowerPlants
4.TerrestrialCommercialFossilFuelPowerPlants
5.TerrestrialSolarPowerPlants
6.AutomobileWasteHeat"Scavenging"
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Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
IMAGEGALLERY
NASA/JSCPropulsionandPowerDivision
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Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
ABSTRACT(CONTINUEDFROMPAGE1)
Forexample,two“small”(6kWe)ThermionicSpaceReactorswereflownbytheUSSRin1987-88foroceanradar
reconnaissance.HigherpoweredNuclear-ThermionicpowersystemsdrivingElectricPropulsion(Q-thruster,
VASIMR,etc.)mayofferthebreakthroughnecessaryforhumanMarsmissionsof<1yrroundtrip.Power
generationonEarthcouldbenefitfromsimpler,moeeconomicalnuclearplants,and"topping"ofmorefueland
emissionefficientfossil-fuelplants.
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Solid-StateThermionicNuclearPowerForMegawattPropulsion,PlanetarySurfaceAndCommercialPowerProject
ANTICIPATEDBENEFITS
ToNASAunfunded&plannedmissions:(CONT'D)couldenableHumanMarsmissionsof<1yearroundtripbyaffordingasystemofmegawattpower,lowspecific
mass(<10kg/kWe),greatlyreducedplantcomplexity,andassociatedsavingsindevelopmentcost.
AdvancedNuclear-ThermionicpowersystemsdrivingElectricPropulsion(Q-thruster,VASIMR,Hall,Ion,MPD,etc.)
mayofferthebreakthroughnecessaryforhumanMarsmissionsof<1yearroundtrip,resultinginsignificant
improvementtocrewhealthandsafety,largereductionsinconsumablesmass,massofsparesandredundancy,
andreduced"window"forcatastrophichardwarefailureorsolarflareevents.
Toothergovernmentagencies:TheDepartmentofEnergy(DOE)SmallModularReactor(SMR)Programmaybenefitfromthisworkintheareaof
efficientandeconomicalcommercialnuclearpowerplantswithfewerparts,fluidloops,andwasteproducts.
Tothenation:Terrestrialapplicationswouldbeinformedandinfusedresultinginhighefficiencypowersystemswithgreatly
reducedcomplexityandcost.Benefitsincludehighconversionefficiency(20%),staticoperationwithnomoving
partsandpotentialforhighreliability,greatlyreducedplantcomplexity,andpotentialforlowerDesign,
Development,TestandEvaluation(DDT&E)costs.Thiscouldleadtomoreefficientandeconomicalnuclearpower
plants,oralternativelyserveasa"topping"cycleinfossilfuelplantstoreducefuelconsumption,emissionsand
cost.Solarpowerplantsmaybecomeamorecompetitiveoption.Automobilesandbusesmayconsumelessfuel
andproducelasswastegasbyscavengingwasteheatfromengineblocksandexhaust.
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